Port heating system and method

ABSTRACT

Methods and systems are provided for operating an engine having a plurality of cylinders that utilize oil for lubrication purposes. In one embodiment, a method for the engine may include determining if one or more conditions have been met for port heating based on one or more operating conditions of the engine, continuing current operation if the one or more conditions for port heating have not been met, and determining a souping level of the engine if the one or more conditions for port heating have been met and subsequently running port heating on a set of cylinders of the engine based on the souping level of the engine and/or the one or more conditions for port heating. The engine may be a non-EGR engine and/or a high speed diesel engine. Each cylinder of the set of cylinders may have at least one port.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application claims priority to Indian Patent Application No.202041031788, entitled “PORT HEATING SYSTEM AND METHOD,” and filed onJul. 24, 2020. The entire contents of the above-listed application arehereby incorporated by reference for all purposes.

BACKGROUND Technical Field

Embodiments of the subject matter disclosed herein relate to internalcombustion engines and, more specifically, to heating cylinder exhaustports.

Discussion of Art

Various engines may have lubrication systems in which pressurized oilcan be used to lubricate and/or cool engine valve train components,camshaft assemblies, pistons, and related engine components. Such oilsystems may supply sufficient oil for both lubrication and cooling ofsuch engines at full load.

In some engines, such as large bore engines designed for significant(e.g., higher performance) operation under full (e.g., rated) load, oilfrom the lubrication system may be retained in the grooves of a cylinderwall and may eventually enter an exhaust system or engine stack. Morespecifically, unburned fuel from combustion during low load conditionsmay contribute to accumulation and deposition of the unburned fuel andoil in the exhaust system, especially at reduced exhaust porttemperatures.

One approach to address such deposits involves regular (e.g., periodic)exhaust system maintenance. In one example, exhaust stack maintenancemay entail service personnel climbing onto a top surface of a locomotiveand manually cleaning the exhaust system. However, frequent exhaustsystem maintenance compounded with the use of complicated manualmaneuvers therein may introduce unwanted delays in engine operation.Another approach involves, during an exhaust gas recirculation (EGR)cooler heating mode, operating at least one donor cylinder at a cylinderload sufficient to increase an exhaust temperature to a level wherelocal oil and fuel accumulation may be burned off. However, thisapproach demands the use of an EGR system and fails to account forengine age or engine souping (e.g., fouling) during long idling periods.Thus, there is a fuel consumption penalty associated with this method.It may be desirable to have a system and method that differ from thosethat are currently available.

BRIEF DESCRIPTION

In one embodiment, a method for an engine may include determining one ormore operating conditions of the engine, determining a load of theengine, determining if one or more conditions have been met for portheating based on the one or more operating conditions of the engine andthe load of the engine, continuing current operation if the one or moreconditions for port heating have not been met, and determining a soupinglevel of the engine if the one or more conditions for port heating havebeen met and subsequently running port heating on a set of cylinders ofthe engine based on the souping level of the engine and/or the one ormore conditions for port heating. The engine may be a non-exhaust gasrecirculation engine and/or a high speed diesel engine. Each cylinder ofthe set of cylinders may have at least one port.

In one embodiment, a system may include a high speed diesel enginehaving cylinders in banks, each cylinder having at least one port, and acontroller that is configured to operate the engine in at least twomodes, with at least one of the at least two modes being a port heatingmode. The controller may further be configured to decrease, for the portheating mode, one or more of a frequency of port heating events and aduration of each port heating event as an age of the engine increases.

In one embodiment, a system may include a high speed diesel enginehaving cylinders in banks, each cylinder having at least one port, and acontroller. The controller may be configured to operate the engine in atleast two modes, with at least one of the at least two modes being aport heating mode. The controller may further be configured to reduce afuel consumption penalty of the port heating mode by decreasing anoperating aspect of the port heating mode based at least in part on acalculated or measured level of souping of the engine.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an example embodiment of a diesel-electric locomotive;

FIG. 2 shows a high level flow chart illustrating a method for anengine, according to an embodiment of the disclosure;

FIG. 3 shows a high level flow chart illustrating an example portheating routine for an engine, according to an embodiment of thedisclosure;

FIG. 4 shows a high level flow chart for a conditioning routine whichmay be performed to prepare an engine for an ensuing port heatingoperation, according to an embodiment of the disclosure;

FIG. 5 shows a non-limiting example of graphical data illustrating atiming advance angle during port heating using the routines presented inFIGS. 3 and 4 as compared to a timing advance angle during normal engineoperation;

FIG. 6 shows a non-limiting example of graphical data illustrating arail pressure during port heating using the routines presented in FIGS.3 and 4 as compared to a rail pressure during normal engine operation;

FIG. 7 shows a non-limiting example of graphical data illustrating anidle time between port heating events using the routines presented inFIGS. 3 and 4; and

FIG. 8 shows a non-limiting example of graphical data illustrating amaximum power limit for running port heating using the routinespresented in FIGS. 3 and 4.

DETAILED DESCRIPTION

The following description relates to a system and method for portheating in engines. Such engines may have lubrication systems thatprovide oil for lubricating valve trains, pistons, and other relatedengine components. Unburned oil and/or fuel may accumulate in an engineexhaust manifold during the course of engine operation. Accordingly,exemplary embodiments of such a lubricating system may interact with acorresponding engine, as controlled by an engine control system, to burnoff otherwise unburned oil and/or fuel and thereby reduce fouling of anexhaust system of the engine. One example of such a configuration isillustrated with reference to FIG. 1, in which a lubricating system mayinteract with a locomotive engine to provide lubrication during engineoperation and an engine controller may enable regular (e.g., periodic)exhaust maintenance.

In one embodiment, an engine controller may switch an engine betweendifferent operating modes. Examples of operating modes may includenormal running mode, low load, high load, high heat mode, startup mode,restricted oxygen mode, and the like. Under normal running conditions,oil used to lubricate a piston can carry over into a combustion chamberand work its way into an exhaust system. During extended periods of lowload operation, exhaust temperatures may not be high enough to burn offthis oil carry-over. Carry-over, souping (e.g., fouling), and/orexcessive soot generation may result in wet oil or soot from within theexhaust system being deposited near the engine, such as on the exteriorof a vehicle housing the engine and/or back into an air intake systemvia EGR (where applicable). In one embodiment, a technical effect mayinclude using port heating to mitigate oil carry-over. Port heating maybe accomplished by, for example, over-fueling one or more cylinders toincrease exhaust temperatures and locally burn off any oil accumulationbefore it can travel downstream of corresponding cylinder exhaustport(s). As further elaborated in FIGS. 2-4, control routines may beperformed to initiate port heating without EGR cooler regeneration,where the port heating is graduated out over time and heating isweighted by engine age/souping level (in contrast with current methods).In this way, a fuel penalty associated with cylinder port heating may beminimized, taking advantage of a reduction in souping over time as theengine breaks in.

In one embodiment, a system may include a high speed diesel enginehaving cylinders in banks, each cylinder having at least one port, and acontroller that can operate the engine in at least two modes, with atleast one of the at least two modes being a port heating mode. Thecontroller may switch to the port heating mode based on one or moretriggers. Suitable triggers may include one or more of a function oftime and an age of the engine, wherewith the port heating mode may bevaried by decreasing one or more of a frequency of port heating events,a duration of each port heating event, a target temperature of each portheating event, and an amount of fuel used by at least one of thecylinders during each port heating event. For example, one or more ofthe frequency of port heating events and the duration of each portheating event may be decreased based on the age of the engine. In someexamples, the age of the engine may be a measured or calculatedmegawatt-hours (MWh) of the engine. A high speed diesel engine may haveits highest power output of approximately 5 MW. As non-limitingexamples, the high speed engine may be used to power vehicles, trucks,buses, cars, yachts, shipping vessels, compressors, pumps, and/orgenerators.

In another embodiment, a system includes a high speed diesel enginehaving cylinders in banks, each cylinder having at least one port, and acontroller. The controller may be configured to operate the engine in atleast two modes, with at least one of the at least two modes being aport heating mode. The controller may further be configured to decreasean operating aspect of the port heating mode based at least in part on acalculated or measured level of souping of the engine. FIGS. 5 and 6show example graphical representations of an advanced angle timing and arail fuel pressure, respectively, during each of normal operation andport heating using the routine described with respect to FIGS. 3 and 4.

The approach described herein may be employed in a variety of enginetypes and sizes and speeds, and in a variety of engine-driven systems.Some of these systems may be stationary while others may be onsemi-mobile or mobile platforms. Semi-mobile platforms may be relocatedbetween operational periods, such as while mounted on flatbed trailers.Mobile platforms may include self-propelled vehicles. Such vehicles mayinclude on-road transportation vehicles (e.g., automobiles), miningequipment, marine vessels, rail vehicles, and other off-highway vehicles(OHVs). A locomotive is provided as an example of a mobile platformsupporting a system incorporating an embodiment of the disclosure. Asuitable non-vehicle application may include a station power generator.

In one embodiment, a platform is disclosed for an engine disposed in avehicle. FIG. 1 is a block diagram of an example vehicle system having arail vehicle. In the illustrated embodiment, the rail vehicle isdepicted as a locomotive 100 with a main engine housing 102 that cantravel on a track 104. Further, the locomotive may be a diesel electricvehicle operating a diesel engine 106 that is located within the enginehousing. In alternative embodiments, a suitable engine may consume orutilize various fuels and oils other than diesel fuel and lubricatingoil. Suitable other fuels may include gasoline, kerosene, alcohol,natural gas, biodiesel, and mixtures of two or more thereof. The enginemay include a plurality of cylinders 107. In one example, engine mayinclude twelve cylinders (e.g., two banks of six cylinders each).Further, the plurality of cylinders in the engine may include varioussets and subsets of cylinders, such as a first subset of cylinders 109 aand a second subset of cylinders 109 b. In some embodiments, each subsetof cylinders may include one or more donor cylinders (e.g., dedicated togenerating exhaust for an EGR operation) and one or more non-donorcylinders (e.g., one or more remaining cylinders which are not donorcylinders). In other embodiments, the first subset of cylinders mayinclude only donor cylinders and the second subset of cylinders mayinclude only non-donor cylinders, for example. The various sets andsubsets of cylinders may include one or more cylinder groups forselected operating modes, as described herein. In alternate embodiments,alternate engine configurations may be employed, such as a gasolineengine or a biodiesel or natural gas engine, for example.

An operating crew and electronic components involved in vehicle systemscontrol and management may be housed within a locomotive cab 108. In oneexample, a controller 110 may include a computer control system and/oran engine control system. The locomotive control system may havenon-transitory computer readable storage media (not shown) includingcode for enabling an on-board monitoring and control of locomotiveoperation. The controller may oversee vehicle systems control andmanagement and may receive signals from a variety of sources to estimatevehicle operating parameters. The controller may be linked to a display(not shown) to provide a user interface to the vehicle operating crew.In one embodiment, the controller may be configured to operate with anautomatic engine start/stop (AESS) control system on an idle vehicle100, thereby enabling the vehicle engine to be automatically started andstopped upon fulfillment of AESS criteria as managed by an AESS controlroutine.

The engine may be started with an engine starting system. In oneexample, a generator start may be performed wherein the electricalenergy produced by a generator or alternator 116 may be used to startthe engine. Alternatively, the engine starting system may use a motor tostart the engine. Suitable motors may include an electric starter motoror a compressed air motor. The engine may be started using energy froman energy storage device, such as a battery, or other appropriate energysource.

The diesel engine generates a torque that is transmitted to thealternator along a drive shaft (not shown). The generated torque is usedby the alternator to generate electricity for subsequent propagation(e.g., propulsion) of the vehicle. The electrical power generated inthis manner may be referred to as the prime mover power. The electricalpower may be transmitted along an electrical bus 117 to a variety ofdownstream electrical components. Based on the nature of the generatedelectrical output, the electrical bus may be a direct current (DC) bus(as depicted) or an alternating current (AC) bus. Various powerelectronics components may be used to manage the electrical current.

The engine may be operated under a plurality of load levels and/or aplurality of engine speeds. These load levels may range from idle on thelow end to a peak engine output on the high end. Low engine load mayinclude operation at a lower end of the engine load range. Mid-engineload may include operation at a mid-level of the engine load range abovelow load. High engine load may include operation at a higher end of theengine load range above mid-engine load. While the engine may operate ata given engine load, each cylinder may have a variable cylinder load.These cylinder loads may range from cylinder low-load to cylinderhigh-load. The engine load and the cylinder load(s) may coincide in someinstances, while not in other instances. For example, the engine overallmay be operated under low load, however, some cylinders may be operatedat substantially no-load (e.g., deactivated), while other cylindersoperate at a mid- to high-load, depending on the number of cylindersoperating at the different loads. Further, a cylinder fuel injectionamount may set a cylinder's load. For example, a cylinder operatingwithout fuel injection may be considered deactivated (in which case itmay be referred to as skip fire operation), while a cylinder operatingwith low fuel injection may be considered to be operating underlow-load.

The alternator may be connected in series to power electronics havingone or more rectifiers (not shown) that convert the alternator'selectrical output to DC electrical power prior to transmission along theDC bus. Based on the configuration of a downstream electrical componentreceiving power from the electrical (e.g., DC) bus, one or moreinverters 118 may be configured to invert the electrical power from theelectrical bus prior to supplying electrical power to the downstreamcomponent. In one embodiment, a single inverter may supply AC electricalpower from a DC electrical bus to a plurality of components. In analternate embodiment, each of a plurality of distinct inverters maysupply electrical power to a distinct component. For example, eachdistinct inverter may supply electrical power to a different, distinctcomponent from each other distinct inverter. The vehicle may include oneor more inverters connected to a switch that may be controlled toselectively provide electrical power to different components connectedto the switch.

A traction motor 120, mounted on a truck 122 below the main enginehousing, may receive electrical power from the alternator via the DC busto provide traction power to propel the vehicle. As described herein,the traction motor may be an AC motor. Accordingly, an inverter pairedwith the traction motor may convert the DC input to an appropriate ACinput, such as a three-phase AC input, for subsequent use by thetraction motor. In alternate embodiments, the traction motor may be a DCmotor directly employing the output of the alternator afterrectification and transmission along the DC bus. One example vehicleconfiguration may include one inverter/traction motor pair perwheel-axle 124. As depicted herein, six pairs of inverter/tractionmotors are shown for each of six pairs of wheel-axle of the vehicle. Forexample, each inverter/traction motor pair may be associated with adifferent wheel-axle. In alternate embodiments, the vehicle may havefour inverter/traction motor pairs. In alternative embodiments, a singleinverter may be paired with a plurality of traction motors.

The traction motor may act as a generator providing dynamic braking tobrake the vehicle. In particular, during dynamic braking, the tractionmotor may provide torque in a direction that is opposite from therolling direction thereby generating electricity that is dissipated asheat by a grid of resistors 126 connected to the electrical bus. In oneexample, the grid may include stacks of resistive elements connected inseries directly to the electrical bus. The stacks of resistive elementsmay be positioned proximate to the ceiling of the main engine housing inorder to facilitate air cooling and heat dissipation from the grid. Insome embodiments, air brakes (not shown) making use of compressed airmay be used by the vehicle as part of a vehicle braking system. Thecompressed air may be generated from intake air by a compressor 128.

A multitude of motor driven airflow devices may be operated fortemperature control of vehicle components. The airflow devices mayinclude, but are not limited to, blowers, radiators, and fans. A varietyof blowers (not shown) may be provided for forced-air cooling of variouselectrical components. For example, such blowers may include a tractionmotor blower to cool the traction motor during periods of heavy work, analternator blower to cool the alternator, and a grid blower to cool thegrid of resistors. Each blower may be driven by an AC or DC motor andaccordingly may be configured to receive electrical power from the DCbus by way of a respective inverter.

Engine temperature may be maintained in part by a radiator 132. Watermay be circulated around the engine to absorb excess heat and containthe engine temperature within a desired range for efficient engineoperation. The heated water may then be passed through the radiatorwherein air blown through a radiator fan may cool the heated water. Theradiator fan may be located in a horizontal configuration proximate to arear ceiling of the vehicle such that. upon blade rotation, air may besucked from below and exhausted. A cooling system including awater-based coolant may optionally be used in conjunction with theradiator to provide additional cooling of the engine.

An on-board electrical energy storage device, represented by battery 134in this example, may be linked to the DC bus. A DC-DC converter (notshown) may be disposed between the DC bus and the battery to allow ahigh voltage of the DC bus (for example, in the range of 1000 V) to bestepped down appropriately for use by the battery (for example, in therange of 12-75 V). In the case of a hybrid vehicle, the on-boardelectrical energy storage device may be in the form of high voltagebatteries, such that placement of an intermediate DC-DC converter maynot be necessitated. The battery may be charged by running the engine.The electrical energy stored in the battery may be used during astand-by mode of engine operation, or when the engine is shut down, tooperate various electronic components such as lights, on-boardmonitoring systems, microprocessors, processor displays, climatecontrols, and the like. The battery may be used to provide an initialcharge to start-up the engine from a shut-down condition. In alternateembodiments, the on-board electrical energy storage device may be asuper-capacitor, for example.

A lubrication system 140 may include a pressure fed oil system with acrank driven oil pump for lubricating the engine crankshaft, valves, andpistons. A reservoir of oil may be stored in a sump below the engine.The valves may be lubricated with splash oil while cylinder liners maybe lubricated by pressurized oil being fed into the piston(s), off thecrankshaft, for both cooling and lubricating purposes. Carry-over of oilinto the combustion chamber (e.g., cylinder) may be controlled by pistonrings. As such, the piston rings may be shaped to allow enough oil toreach a top piston ring and lubricate it when the cylinder is working atfull load. Gas pressure balance in piston ring grooves may furthercontrol carry-over of oil into the combustion chamber. Oil may drain outbelow an oil control ring and, as the piston moves up and down thecylinder liner, the oil control ring may remove the majority of this oilby scraping. The remaining oil may be carried by remaining piston ringsto provide them sufficient lubrication. If the oil gets heated duringpassage around the engine, it may be cooled by passage through theradiator. An exhaust stack 142 may receive exhaust gas from the engineand directs it away therefrom. Ducts or tubing (not shown) may beprovided between the crankcase (holding the lubricating oil) and theexhaust stack for ventilating the crankcase, for example, forventilating blow-by gas from the crankcase.

The lubrication system may supply sufficient oil for a full loadoperation. However, at light loads, an excess amount of oil may besupplied. For a given cylinder, some of the excess oil may be carriedinto the cylinder (e.g., combustion) chamber and corresponding exhaustport. Oil in the combustion chamber may originate from oil retained ingrooves of cylinder liner walls. As such, the engine may retain some oilin the grooves to provide lubrication for the pistons and rings.Carry-over oil in the combustion chamber may also be contributed by oillubricating the valves. Herein, oil moves down the valves to providelubrication between the valve and a corresponding valve guide, andfurther at a seating surface of the valve on a cylinder head. In someinstances, when the engine has accumulated a few hours of operation, anoil carry-over condition may be more severe and the condition may beexacerbated by the carry-over of excess lubrication oil into anassociated turbocharger over a period of time. Thus, the controllercommunicating with the engine system may enable a port heating routine,as further elaborated in FIGS. 3 and 4, to allow any unburned oil to beburned off and avert degraded engine performance due to accumulation ofthe unburned oil. It will be appreciated that the routine may also allowunburned fuel as may have accumulated in the combustion chamber due topoor fuel combustion under low load conditions to be burned off.Alternatively, an engine may break in after some use, and before beingworn out, so as to decrease a risk of souping. In such instances, thecontroller may reduce or eliminate the port heating routine. Variouscontrol algorithms may be employed based on, for example, measuring ofan actual souping amount at various locations, indirect factors (such assoot production or exhaust opacity), or calculating based on engine age(e.g., MWh produced), duty cycle, etc.

FIG. 2 depicts an example method 200 of determining if (e.g., underwhich conditions) a port heating mode of operation may be carried outwithin a non-EGR engine and/or a high speed internal combustion engine.The method may be performed by a control system, or a controller, incommunication with an engine to enable exhaust port heating andsubsequent burning of unburned oil and/or fuel. The control system mayoperate in at least two modes, with at least one of the at least twomodes being a port heating mode. During engine operation, the controllermay change an operating aspect of the port heating mode based at leastin part on a calculated or measured level of souping of the engineand/or engine age.

At step 202, the method may include determining one or more engineoperating conditions. The one or more engine operating conditions mayinclude an engine idling condition, an idling time, an engine load, anengine loading time, an engine age, an engine speed, and the like. Atstep 204, the method may include determining the engine load (e.g., ifnot determined at step 202). As described above, the engine load mayrange from idle on a low end of an engine load range to peak engineoutput on a high end of the engine load range. At step 206, the methodmay include determining if conditions have been met for port heating.Conditions that may be met may include when the engine load is below athreshold load (e.g., low load), after the engine has experiencedconditions that put the engine at risk for oil in the exhaust gas (e.g.,after the engine has been at low load for a duration that may be arelatively extended period of time), when the engine is operating atidle, or during dynamic braking. During operation with the engine loadbelow the threshold load, select cylinders may operate with a highercylinder load (e.g., via the port heating mode) such that exhaust porttemperatures are increased to remove deposits. In one non-limitingexample, the cylinders operating with the higher cylinder load maycorrespond to ˜99.9% torque production at a given engine speed. Forinstance, the higher cylinder load may correspond to 385 kW within aport heating engine speed range of 840 to 1800 rpm. Remaining cylindersmay be operated with a lower cylinder load, the lower cylinder load lessthan the higher cylinder load. For instance, the lower cylinder load maycorrespond to less than 80 kW. Accordingly, the remaining cylinders mayregulate the given engine speed (e.g., according to a value selectedfrom the port heating engine speed range).

In another example, the controller may determine one or more ofaccumulated engine revolutions at low or no load, a load amount, andengine revolutions as a function of MWh as factor(s) in determiningwhether to initiate port heating. For example, the engine speed, theengine load, the engine age (e.g., in MWh), and/or time may be takeninto account so that differential port heating is engaged at multiplespeeds (e.g., different speed levels may trigger different levels ofport heating). In one embodiment, one or more idle timer criteria may beused to determine if the condition(s) have been met for port heating.The idle timer may be based on different engine speeds [e.g., a firstspeed, a second speed, a third speed (high speed, medium speed, lowspeed), etc.] as well as different engine ages and normalized to anengine revolution count [e.g., by using a two-dimensional (2D) table ofmultipliers determined as a function of the engine speed and the engineage in MWh]. A normalized engine revolution counter limit may be used asa threshold counter to enable port heating. In one embodiment, thenormalized engine revolution counter limit may be expressed as aone-dimensional (1D) vector (e.g., as a function of the engine age inMWh).

If conditions for port heating have not been met, the method may proceedto step 208, where the method may include continuing current engineoperation. If conditions for port heating have been met, the method mayproceed to step 210, where the method may include determining the engineage and a souping level of the engine (although, in some examples, theengine age may be determined at step 202 and only the souping level ofthe engine may be determined at step 210). During idling of dieselengines for extended periods of time, souping may occur where asignificant fraction of engine emissions is not emitted but retained as“soup” (e.g., semi-volatile hydrocarbons and lubricating oil) to besubsequently emitted when the engine returns to higher-load operation.This soup may accumulate and form unwanted deposits downstream ofcylinder exhaust ports. Accordingly, at step 212, the method may includerunning port heating on a set of cylinders (e.g., a portion or all ofthe cylinders in the engine) based on the engine age, the souping level,and/or the port heating conditions met. In one embodiment, the controlsystem may operate in at least two modes, with at least one of the atleast two modes being a port heating mode. During engine operation, thecontroller may change (e.g., decrease) one or more operating aspects ofthe port heating mode based on one or more factors (e.g., a function oftime, the engine age in measured or calculated MWh of the engine, etc.),the one or more operating aspects including one or more of a frequencyof port heating events, a duration of each port heating event, a targettemperature of each port heating event, and an amount of fuel usedduring each port heating event. For example, the controller maydecrease, for the port heating mode, one or more of the frequency ofport heating events and the duration of each port heating event based onthe engine age.

FIG. 3 depicts an example routine 300 by executable a control system,such as a controller, in communication with an engine, such as a non-EGRengine and/or a high speed diesel engine, to enable exhaust port heatingand subsequent burning of unburned oil and/or fuel. As such, the routinemay be performed as part of, or may wholly substitute, the port heatingstep (step 212) of method 200, as described in detail above withreference to FIG. 2. As a non-limiting example, the routine may operatewithin a vehicle system for a rail vehicle (e.g., a locomotive). Theoperation may consider one or more engine operating conditions, such asan engine idling condition, an engine age, an engine speed, an idlingtime, an engine load, an engine loading time, and initiate a portheating operation based on the one or more engine operating conditions.The port heating operation may vary dependent on one or more of theengine age, a souping level of the engine, and the engine speed. In thisway, as there is less demand for port heating as the engine breaks in, afuel consumption penalty associated with port heating may be reducedover time. For example, variation in port heating may include decreasingthe frequency and/or duration of port heating events over time andengine use (e.g., as the engine age increases), with differential portheating engaged in response to different thresholds or ratios being met[e.g., different speed, rail pressure (RP), or advanced angle (AA)ratios/ranges].

In one example, the port heating operation may include successivelyoperating distinct subsets of cylinders at a cylinder load or a fuelinjection amount sufficient to increase an exhaust temperature of thesubset for burning unburned fuel and/or oil deposited in the subsetand/or an exhaust system coupled thereto, while operating the engine inan overall low-load mode or an idle mode. During such operation, eachsuccessively operated subset of cylinders may include at least twocylinders at a time from the same cylinder bank. For example, eachsuccessively operated subset of cylinders may include exactly twocylinders at a time from the same cylinder bank. Cylinders that are notcurrently being operated in the subset are operated in a low- or no-fuelmode. The successive operation may include first operating a firstsubset of cylinders in the port heating mode, and then operating adifferent, second subset of cylinders in the port heating mode, and soon. Further, the distinct subsets may have cylinders in common, but eachsubset may be different from the others in terms of at least onecylinder. In some examples, such as when the engine is the non-EGRengine, the subsets may not be selected or distinguished based onwhether the cylinders therein are donor or non-donor cylinders. In thisway, it is possible to remove hydrocarbon deposits from exhaust of allof the cylinders.

In another example, the port heating may include operating the engine inat least two modes, including a first mode with a lower fuel injectionamount, and a second mode with a higher fuel injection amount, thehigher fuel injection amount being higher than the lower fuel injectionamount. Specifically, the operation may include operating at least twoof the cylinders of a cylinder bank (e.g., a right bank) in the secondmode while at least another cylinder of an opposite cylinder bank (e.g.,a left bank) operates in the first mode to increase the exhausttemperature at least of the at least two cylinders in the second modeafter a designated amount of low-load engine operation, and during thelow-load engine operation. Thus, even though an overall engine load maybe low, select cylinders may operate with a higher cylinder load tothereby generate sufficient exhaust port temperatures to removedeposits, at least for that select cylinder. By changing which cylindersoperate in each mode, different cylinders may have their respectiveexhaust systems cleaned of deposits. Such operation may continue untilall cylinders have been operated with port heating, or until the engineload is increased away from idle or low-load operation (e.g., due totraveling conditions of the vehicle). In such cases, if the engineoperates at sufficiently higher load, the port heating may bediscontinued (e.g., any cylinders that had not yet been operated in thesecond mode would have been cleaned by the higher load operation, andthus it may be unnecessary to resume the port heating). However, if theload conditions were not sufficiently high, or were performed for tooshort of a duration, the port heating may resume where it left off.

Examples of the above operation, along with variations and additionaloperations are described with reference to the routine of FIG. 3. Atstep 302, the routine may include starting (but not yet incrementing) anidle timer, where an initial setting of time zero is indicated. The idletimer may measure an amount of time spent by the engine in idlingconditions. In one example, the idling conditions may include thevehicle parked on a siding for a relatively long duration with theengine running at an idling speed. In some examples, a load timer mayalso be started (but not yet incremented) at step 302, where an initialsetting of to time zero is indicated. The load timer may measure anamount of time during which the engine is loaded, e.g., not idling. Atstep 304, the routine may include incrementing the idle timer based onthe amount of time spent in idle mode. At step 306, the routine mayinclude determining whether the amount of time spent in idle mode isgreater than a predetermined or specified maximum idle time. In oneexample, the predetermined maximum idle time may be 6 hours. In anotherexample, the predetermined maximum idle time may be 60 min or less.Additionally or alternatively, the predetermined maximum idle time maybe a function of the engine speed. For example, the predeterminedmaximum idle time may be decreased with increasing engine speed (e.g.,the predetermined maximum idle time may be decreased from 60 min at 500rpm to 0 min at 1200 rpm). If the amount of time spent in idle mode isgreater than the predetermined maximum idle time, the routine mayproceed to step 308, where the routine may include conditioning theengine for port heating. Note that the idle time may be a continuousidle time (e.g., without interruptions of other operating modes) or mayinclude a plurality of idle conditions which together reach thepredetermined maximum idle time.

While the depicted example uses fulfillment of idle timer criteria forenabling port heating, in alternate embodiments, other criteria may beused in addition to the idle timer criteria. As one example, an engineidling speed may be determined and if the engine idling speed is above apredetermined port heating speed limit, then the port heating operationmay be disabled. As elaborated further in FIG. 4, a conditioningprocedure may include identifying a first target cylinder where portheating may be initiated and an order of cylinders to follow. Further,the conditioning procedure may entail determining injection settings,slew rates, and port heating speeds. Once the engine has beenappropriately conditioned, the routine may include running a portheating operation at step 310. Alternatively, if the routine is beingrestarted after a previously interrupted port heating operation, then atstep 310 the port heating operation may be resumed.

Following running (or resumption) of the port heating operation, at step312, the routine may include determining whether the engine is in idlemode (e.g., meeting one or more idle conditions). If the engine isidling, the routine may proceed to step 314, where the routine mayinclude determining whether the port heating operation has beencompleted or not. If the port heating operation has been completed, theroutine may include stopping further port heating at step 316 andresetting the idle timer to zero at step 318. However, if at step 312 itis determined that the engine is not idling (e.g., it is determined thatthe engine is operating at a higher load condition), the routine mayinclude suspending port heating at step 320. The routine may proceed tostep 322, where the routine may include determining if one or moreengine load conditions meets load timer criteria, as further elaboratedbelow.

As such, unburned oil and/or fuel accumulation may occur duringprolonged engine idling conditions. However, during engine operation atnon-idling conditions, an engine exhaust manifold may incur temperaturerises which may spontaneously burn off the accumulated unburned oiland/or fuel. Thus, during engine operation at non-idling conditions, theport heating operation may be suspended or may not be executed at all.In this way, the routine may adjust a port heating operation to occurwhen the engine is idling for a sufficient duration, e.g., when apossibility of unburned oil accumulation is higher. Correspondingly, theroutine may suspend the port heating operation when the engine isrunning at higher loads and thus when the unburned oil may be burned offduring a normal course of the engine's operation. While operation athigher load is one example, various operations may trigger suspension ofthe port heating mode (e.g., an operator throttle request, cold ambienttemperatures, engagement of an auxiliary load, etc.).

Returning to step 306, if the amount of time spent in idle mode is notgreater than the predetermined maximum idle time, the routine mayproceed to step 322, the routine may include determining if the enginehas been loaded for a minimum load time (e.g., whether a minimum loadtimer duration has been met). As discussed above, upon suspension ofport heating operations of a loaded engine at step 320, the routine maysimilarly determine whether the minimum load time has been reached atstep 322. If the engine has been loaded for at least the minimum loadtime, then further port heating may not be requested in anticipation ofexhaust temperature rises sufficient to burn off the accumulatedunburned oil and/or fuel. Accordingly, if the minimum load time has beenreached, the routine may proceed to step 323, port heating may not ensueand the routine may include resetting the idle timer to zero.

However, if neither the maximum idling time is met at step 306, nor theminimum load time is met at step 322, the routine may proceed to step324, where the routine may include determining if the engine is still inidle mode. If the engine is still idling, the routine may return to step304 to continue incrementing the idle timer and thereafter proceed withthe port heating operation when/if the idling time criteria is met. Ifthe engine is not idling at step 324, the routine may proceed to step325, where the routine may determine if resumption of idling isrequested (e.g., the minimum load time may not be reached and yetresumption of idling may be requested). If resumption of idling isrequested, the routine may return to step 304 as described above. Ifresumption of idling is not requested, the routine may proceed to step326, where the routine may include incrementing the load timer (e.g.,instead of the idle timer). At step 328, the routine may includeverifying whether a port heating operation had been suspended on aprevious iteration of the routine. If the port heating operation hadbeen previously suspended, the routine may proceed to step 330, wherethe routine may include resuming the port heating operation. If aprevious iteration of the port heating operation had not beeninterrupted, the routine may return to step 322, where the routine maycontinue determining whether the minimum load time has been reached and,at step 326, incrementing the load timer until the minimum load time isreached (following which the need for the port heating operation may benegated and consequently the idle timer may be reset to zero).

As such, at least two criteria may be considered in the determination ofwhether or not to proceed with a port heating operation. The at leasttwo criteria may include a time spent in an idling mode (as may bedefined by an idle timer) and an engine load condition (as may bedefined by a load timer and/or a loaded or non-idle condition of theengine). However, in certain examples, even if the accumulation ofunburned oil and/or fuel would present a potential issue during idle orlow engine load conditions, the temperature of the exhaust manifold maybe raised enough to allow the accumulated unburned fuel and/or oil to beburned during operation of the engine in a sufficiently loaded conditionof sufficient duration.

In one example scenario, the engine may be in an idling condition andmay have spent enough time in the idling condition to warrant a portheating operation to avert adverse effects of accumulated unburned oil.In this scenario, where an idle timer criterion is met, the port heatingoperation may ensue. Upon completion of the port heating operation, theidle timer may be reset to allow a new, subsequent iteration of the portheating operation to follow at a later time (e.g., following a durationwith no port heating). In another example, the engine may not be idling,and may instead be loaded. In such an example, the engine may have spentenough time in the loaded condition to fulfill a load timer criterionand ensure high exhaust manifold temperatures such that a port heatingoperation may not be requested. Moreover, as long as the enginemaintains operation in non-idling conditions, and the load timercriterion is met, the idle timer may remain at zero.

In yet another example, the engine may be idling, but not yet for longenough to fulfill the idle timer criterion. Further, the idlingcondition of the engine may be interrupted by a sudden operation of theengine in a loaded condition. If the interrupting operation of theengine in the loaded condition continues long enough to fulfill the loadtimer criterion, then the exhaust manifold temperatures may again beexpected to reach desirable high temperatures to allow the unburned oilto be burned off, such that upon returning to the idling condition, aport heating operation may not be requested, and the idle timer may bereset to zero. However, if the interrupting operation of the engine inthe loaded condition is not long enough to fulfill the load timercriterion, then upon completion of the loaded engine operation, theengine may return to the idling condition and resume determination ofidle timing.

In still another example, the engine may have idled long enough tofulfill the idle timer criterion and proceeded to run a port heatingoperation. However, the port heating operation may be interrupted by asudden operation of the engine in a loaded condition. First, the idlecondition interrupting running of the engine may result in the portheating operation being suspended. Further, if the engine is run longenough to fulfill the load timer criterion, unburned oil and/or fuel maybe purged and thus the port heating operation may be aborted/abandonedand the idle timer may be returned to zero in anticipation of a newiteration of the port heating operation. However, if the engine is runonly for a shorter amount of time (e.g., not enough to fulfill the loadtimer criterion) and then returned to the idling condition, the portheating operation may be resumed in anticipation of accumulation andsubsequent purging of the unburned oil and/or fuel. In this way, acontrol system may be configured to anticipate accumulation, purging,and/or burning of unburned oil in an engine exhaust manifold based onthe amount of time spent by the engine in idling conditions vis-à-visrunning (or loaded) conditions. Accordingly, by judiciously adjusting aport heating operation, potential issues related to unburned oil buildupmay be averted. Further details of a (pre)conditioning procedure, aswell as a running/resumption of the port heating operation, areelaborated below in the context of FIG. 4.

FIG. 4 depicts an example routine 400 that may be performed by a controlsystem to condition an engine, such as a non-EGR engine and/or a highspeed diesel engine, for a subsequent running (or resumption) of a portheating operation. As such, the routine may be performed as part of, ormay wholly substitute, the conditioning step (step 308) of routine 300,as described in detail above with reference to FIG. 3. The routine maydetermine an order of cylinders to be purged of their unburned oilbuildup. Further, the routine may allow port heating to be adjustedresponsive to an engine age, an engine speed, and a souping level if theengine. At step 402, the routine may include determining whether a portheating state machine is in a “RUN” mode (as opposed to a “HOLD” mode).The routine may continue (to step 404; see below) if the “RUN” mode hasbeen selected, which in turn may depend upon each of one or more portheating operation criteria being met. If the port heating state machineis not in the run mode (e.g., is in the “HOLD” mode), the routine mayend (e.g., continue to step 310 as described in detail above withreference to FIG. 3).

At step 404, the routine may include selecting a target set of cylindersfrom a cylinder bank for initiating cylinder purging (e.g., the portheating operation). Further, a subsequent order of cylinder purgingoperation may be determined. For example, based on various engineconfigurations, the engine may be divided into heating and non-heatingports (e.g., based on cylinder banks). In one example, the engine may bea V-12 engine with two banks of six inline cylinders having a log-typeexhaust manifold for each bank. The target set of cylinders may beselected from a first bank (e.g., a right bank) with the cylinders in asecond bank (e.g., a left bank) including the non-heating ports. In thisconfiguration, an order of port heating may include starting with thetarget set of cylinders in a designated bank and successively portheating remaining sets of cylinders within the same bank. Further, the(target) cylinder sets may be selected to take advantage of previouslyheated neighboring cylinders so that the cylinder that may have thegreatest accumulation of exhaust hydrocarbons may experience a longestduration of high temperature exhaust. In some examples, port heating maybe operated within an entire bank as opposed to cylinder sets within thebank, which may demand the non-heating bank to receive normal fueling.In some examples, such as when the engine is the non-EGR engine, thetarget cylinder sets may not be selected or distinguished based onwhether the cylinders therein are donor or non-donor cylinders.

At step 406, the routine may include determining one or more portheating settings for the target cylinder set. The one or more portheating settings may be determined based on at least one of an enginespeed, an engine age (e.g., accumulated MWh), a (calculated or measured)souping level of the engine, and an idle time. As an example, anoperating aspect (e.g., duration, temperature, amount of over-fueling,etc.) of the port heating may be decreased based at least in part on thesouping level of the engine, thereby reducing an associated fuelconsumption penalty over time. As another example, a target temperatureand/or a duration of port heating may be determined based on currentengine demand for established speed, RP, and/or AA ranges or ratios. Forinstance, in such an example, a first set of port heating settings maybe determined for high speed engine conditions (e.g., corresponding to ahigher engine speed), a second set of port heating settings may bedetermined for medium speed engine conditions (e.g., corresponding to anintermediate engine speed lower than the higher engine speed), and/or athird set of port heating settings may be determined for low speed oridle engine conditions (e.g., corresponding to a lower engine speedlower than each of the higher and intermediate engine speeds).

In one example, the high speed engine conditions may include an enginespeed ranging from 1200 to 1800 rpm, an AA ranging from 17 to 24degrees, and/or an RP ranging from 800 to 1000 bar. The medium speedengine conditions may include an engine speed ranging from 600 to 1200rpm, an AA ranging from 5 to 17 degrees, and/or an RP ranging from 600to 800 bar. The low speed or idle engine conditions may include anengine speed ranging below 600 rpm, an AA ranging below 5 degrees,and/or an RP ranging below 600 bar. Alternatively, the one or more portheating settings may be varied based on different engine speed, MWh, RP,and/or AA ratios (e.g., the target temperature or the duration of portheating may increase by a specified amount for a specified speedincrease relative to the engine age in MWh). For example, the durationand the target temperature of port heating may be decreased at thehigher speed conditions as compared to that during the lower speed or(idling) or medium speed conditions. In an additional or alternativeexample, during the high speed engine conditions, the engine may becontrolled to drop to an rpm level below “high speed” as part of theport heating settings. During the medium or low speed (or idling) engineconditions, the settings for port heating may not include shifting rpmlevels.

In one example, the one or more port heating conditions may be variableabove a high speed threshold based on the engine age (e.g., in MWh)and/or a function of time whereas under the high speed threshold the oneor more port heating conditions may be fixed. For example, at or above1200 rpm, the target temperature of the port heating, the duration ofthe port heating, a frequency of port heating (e.g., of individual portheating events), and/or an amount of fuel used by at least one cylinderduring the port heating may be varied. For speeds below 1200 rpm, thetarget temperature of the port heating, the duration of the portheating, the frequency of the port heating, and/or the amount of fuelused by the at least one cylinder during the port heating may be set atfixed values, the fixed values independent of the engine age and/or thefunction of time. In one example, the duration of the port heating maybe fixed at 18 min for every 60 min of operation for all speeds under1200 rpm whereas the duration of port heating may vary based on time ofoperation and/or other factors for engine speeds at or above 1200 rpm.

In another example, the duration of the port heating may be fixed at 18min for all speeds under 1200 rpm, interrupted by idle times of 60 minor less. In some examples, and as described in greater detail below withreference to FIG. 7, the idle time (between port heating events) maydepend upon the engine speed. For example, at 500 rpm, the duration ofthe port heating may be 18 min and the idle time may be 60 min. Above1200 rpm, port heating may not be operated on a cyclic basis and mayinstead be operated on a continuous basis (e.g., without interruptionsor excursions into idling or other modes). In such examples, and asdescribed in greater detail below with reference to FIG. 8, the portheating may only be run at low-load or idling conditions of the engineaccording to an engine-speed dependent maximum power limit. In oneexample, upon requesting idling, the engine may idle for the idle timeprior to running port heating.

The controller may operate to adjust (e.g., decrease) an operatingaspect of the port heating mode or event based at least in part on thecalculated or measured level of souping of the engine. In one example,the level of souping of the engine may be calculated by subtractingemissions during a soup test baseline from emissions during a soup test,and then dividing by a number of minutes of idle operation between thesoup test baseline and the soup test. The calculated amount of soupingmay be used to adjust the operating aspect of the port heating toincrease efficiency/decrease variation of cleaning as well as reduce thefuel consumption penalty associated with the port heating over time. Forexample, the target temperature and the duration of the port heating foreach of a plurality of threshold-defined ranges (e.g., engine speedranges) may be decreased at lower levels of souping of the engine (e.g.,as the engine is broken in).

In one example, the port heating mode or event may include over-fuelinga set of cylinders within the bank of cylinders undergoing the portheating (e.g., via actuating a fuel injector of at least two cylindersto increase the amount of fuel injected into the cylinders). An amountof over-fueling (e.g., an amount of additional fuel injected) may bebased on initial port heating settings and further adjusted to accountfor one or more of the engine age, the souping level of the engine, fuelinjector health, fuel injector wear, one or more ambient conditions(e.g., of an external environment, such as ambient temperature,altitude, ambient humidity, etc.), time since last engine overhaul, andthe like. Once the port heating settings have beendetermined/established, they may be communicated to the target cylinderset and, at step 408, the routine may include performing the portheating in the target cylinder set based on the determined port heatingsettings. At step 410, the routine may include setting remainingcylinders (that is, cylinders not part of the target cylinder setselected at step 404) to low cylinder load conditions. Accordingly, insome examples, steps 408 and 410 may be performed simultaneously. Atstep 412, the routine may include feeding a status update back to acontroller upon completion of the port heating in the target cylinderset. At step 414, the routine may include determining whether the targetcylinder set is a last target cylinder set within the same cylinderbank. If the target cylinder set is the last target cylinder set, theroutine may end (e.g., continue to step 310 as described in detail abovewith reference to FIG. 3). If the target cylinder is not the last targetcylinder set, the routine may proceed to step 416, where the routine mayinclude proceeding to a next target cylinder set within the samecylinder bank in the order determined previously at step 404. Theroutine may return to 406 to determine the one or more port heatingsettings for the next target cylinder set and perform the port heatingthereon (at 408).

In another example, the controller may determine one or more ofaccumulated engine revolutions at low or no load, the load amount, andengine revolutions as a function of MWh as factor(s) in determiningwhether to initiate the port heating. The engine speed, the engine load,MWh, and time may further be taken into account so that differentialport heating may be engaged at multiple speeds (e.g., different speedlevels may trigger different levels of port heating). In one embodiment,idle timer criteria may be used to determine if the one or more portheating conditions have been met. The idle timer criteria may be basedon different engine speeds [e.g., a first speed, a second speed, a thirdspeed (high speed, medium speed, low speed), etc.] as well as differentengine ages and normalized to an engine revolution count (e.g., by usinga 2D table of multipliers determined as a function of the engine speedand the engine age in MWh). A normalized engine revolution counter limitmay be used as a threshold counter to enable port heating. In oneembodiment, normalized engine revolution counter limit may be expressedas a 1D vector (e.g., as a function of the engine age in MWh).

FIGS. 5 and 6 show non-limiting examples of the AA and the RP,respectively, at different engine speeds during port heating using theroutines presented in FIGS. 3 and 4 as compared to the AA and the RP,respectively, at different speeds during normal engine operation. Asshown in a graph 500 of FIG. 5, the AA may be decreased during portheating events (curve 502) relative to normal engine operation (curve504) at lower engine speeds (e.g., ranging from 500 to 1750 rpm).Similarly, as shown in a graph 600 of FIG. 6, the RP may be decreasedduring port heating events (curve 602) relative to normal engineoperation (curve 604) at lower engine speeds (e.g., ranging from 500 to1500 rpm). Conversely, in certain examples at higher engine speeds(e.g., above 1500 rpm), the RP and AA may be the same as during normalengine operation.

FIGS. 7 and 8 show non-limiting examples of the idle time between portheating events and the maximum power limit for running the port heatingevents, respectively, at different engine speeds. The port heatingevents may be run using the routines presented in FIGS. 3 and 4. Asshown in a graph 700 of FIG. 7, the idle time between the port heatingevents may be decreased as the engine speed increases (curve 702), e.g.,up to a first threshold engine speed. Accordingly, a ratio between theidle time and the duration of each port heating event may decrease asthe engine speed increases up to the first threshold speed.Specifically, at engine speeds between 500 rpm and 1200 rpm, the idletime may decrease from 60 min to 0 min, while a duration of each portheating event may remain fixed (e.g., at 18 min). At and above 1200 rpm(e.g., the first threshold engine speed), the idle time may be 0 min,such that port heating may be run continuously (e.g., withoutinterruptions or excursions into idling or other modes). However, theport heating events may only be run at engine loads less than themaximum power limit. As shown in a graph 800 of FIG. 8, the maximumpower limit may be increased as the engine speed increases (curve 802),e.g., up to a second threshold engine speed. Specifically, at enginespeeds between 500 rpm and 1350 rpm, the maximum power limit mayincrease from 45 kW to 200 kW. At and above 1350 rpm (e.g., the secondthreshold engine speed), the maximum power limit may be 200 kW.

Methods and systems for port heating may be provided to reduce unburnedoil and/or fuel accumulations, e.g., during low-load and/or idle engineoperation. In some examples, cylinder exhaust ports of an engine may besequentially and periodically heated to allow unburned oil therewithinto be evaporated and/or combusted. This may reduce or eliminateundesirable buildup of fuel and/or oil in the cylinder exhaust ports andan exhaust stack downstream. By adjusting port heating operationresponsive to an amount of time spent by the engine in an idlingcondition and further based on an engine load condition, an engine age,and a souping level of the engine, exhaust maintenance may be partiallyor fully automated and human intervention may be reduced.

As used herein, an element or step recited in the singular and precededwith the word “a” or “an” should be understood as not excluding pluralof said elements or steps, unless such exclusion is explicitly stated.Furthermore, references to “one embodiment” or “one example” of theinvention do not exclude the existence of additional embodiments orexamples that also incorporate the recited features. Moreover, unlessexplicitly stated to the contrary, embodiments “comprising,”“including,” or “having” an element or a plurality of elements having aparticular property may include additional such elements not having thatproperty. The terms “including” and “in which” are used as theplain-language equivalents of the respective terms “comprising” and“wherein.” Moreover, the terms “first,” “second,” and “third,” etc. areused merely as labels, and are not intended to impose numericalrequirements or a particular positional order on their objects.

The control methods and routines disclosed herein may be stored asexecutable instructions in non-transitory memory and may be carried outby the control system (e.g., the controller) in combination with thevarious sensors, actuators, and other engine hardware. The specificroutines described herein may represent one or more of any number ofprocessing strategies such as event-driven, interrupt-driven,multi-tasking, multi-threading, and the like. As such, various actions,operations, and/or functions illustrated may be performed in thesequence illustrated, in parallel, or in some cases omitted. Likewise,the order of processing is not necessarily required to achieve thefeatures and advantages of the example embodiments described herein, butis provided for ease of illustration and description. One or more of theillustrated actions, operations and/or functions may be repeatedlyperformed depending on the particular strategy being used. Further, thedescribed actions, operations and/or functions may graphically representcode to be programmed into non-transitory memory of the computerreadable storage medium in the engine control system, where thedescribed actions are carried out by executing the instructions in asystem including the various engine hardware components in combinationwith the electronic controller.

This written description uses examples to disclose the invention,including the best mode, and also to enable a person of ordinary skillin the relevant art to practice the invention, including making andusing any devices or systems and performing any incorporated methods.The patentable scope of the invention is defined by the claims, and mayinclude other examples that occur to those of ordinary skill in the art.Such other examples are intended to be within the scope of the claims ifthey have structural elements that do not differ from the literallanguage of the claims, or if they include equivalent structuralelements with insubstantial differences from the literal languages ofthe claims.

1. A method for an engine, the method comprising: determining one ormore operating conditions of the engine; determining a load of theengine; determining if one or more conditions have been met for portheating based on the one or more operating conditions of the engine andthe load of the engine; continuing current operation if the one or moreconditions for port heating have not been met; and determining a soupinglevel of the engine if the one or more conditions for port heating havebeen met and subsequently running port heating on a set of cylindersbased on the souping level of the engine and/or the one or moreconditions for port heating, wherein the engine is a non-EGR engineand/or a high speed diesel engine, and wherein the engine includes theset of cylinders, each cylinder of the set of cylinders having at leastone port.
 2. The method of claim 1, wherein the one or more conditionsfor port heating comprises an idle time elapsing.
 3. The method of claim2, wherein the idle time decreases as a speed of the engine increases upto a first threshold speed, and wherein the idle time is zero when thespeed of the engine is at and above the first threshold speed.
 4. Themethod of claim 3, wherein the first threshold speed is 1200 rpm.
 5. Themethod of claim 3, wherein running port heating on the set of cylinderscomprises: running port heating between iterations of the idle timeelapsing when the speed of the engine is below the first thresholdspeed; and running port heating without interruption when the speed ofthe engine is at or above the first threshold speed.
 6. The method ofclaim 5, wherein a ratio of the idle time and a duration of port heatingbetween iterations of the idle time elapsing decreases as the speed ofthe engine increases up to the first threshold speed.
 7. The method ofclaim 3, wherein the one or more conditions for port heating furthercomprises an engine load being less than a maximum power limit.
 8. Themethod of claim 7, wherein the maximum power limit increases as thespeed of the of the engine increases up to a second threshold speed, andwherein the maximum power limit is constant when the speed of the engineis at or above the second threshold speed.
 9. The method of claim 8,wherein the second threshold speed is 1350 rpm.
 10. The method of claim2, further comprising determining the idle time based on a speed of theengine and an age of the engine, and normalizing the idle time to anengine revolution count.
 11. The method of claim 1, further comprising,if the one or more conditions for port heating have been met:determining a first set of port heating settings for high speed engineconditions, the high speed engine conditions comprising a speed of theengine ranging from 1200 to 1800 rpm, an advance angle ranging from 17to 24 degrees, and a rail pressure ranging from 800 to 1000 bar;determining a second set of port heating settings for medium speedengine conditions, the medium speed engine conditions comprising thespeed of the engine ranging from 600 to 1200 rpm, the advance angleranging from 5 to 17 degrees, and the rail pressure ranging from 600 to800 bar; and determining a third set of port heating settings for lowspeed or idle engine conditions, the low speed or idle engine conditionscomprising the speed of the engine ranging below 600 rpm, the advanceangle ranging below 5 degrees, and the rail pressure ranging below 600bar.
 12. A system, comprising: a high speed diesel engine havingcylinders in banks, each cylinder having at least one port; and acontroller that is configured to operate the engine in at least twomodes, with at least one of the at least two modes being a port heatingmode, and the controller is further configured to reduce a fuelconsumption penalty of the port heating mode by decreasing an operatingaspect of the port heating mode based at least in part on a calculatedor measured level of souping of the engine.
 13. The system of claim 12,wherein decreasing the operating aspect comprises decreasing at leastone of a frequency of port heating events, a duration of each portheating event, a target temperature of each port heating event, and anamount of fuel used by at least one of the cylinders during each portheating event when the engine operates at or above a set high speedthreshold.
 14. The system of claim 13, wherein the operating aspect ofthe port heating mode is fixed for speeds below the set high speedthreshold.
 15. The system of claim 13, wherein the set high speedthreshold is 1200 rpm.
 16. A system, comprising: a high speed dieselengine having cylinders in banks, at least one of the cylinders havingat least one port; and a controller that is configured to operate theengine in at least two modes, with at least one of the at least twomodes being a port heating mode, the controller being further configuredto decrease, for the port heating mode, one or more of a frequency ofport heating events and a duration of each port heating event as an ageof the engine increases.
 17. The system of claim 16, wherein a subset ofat least two cylinders within a first bank operate in the port heatingmode and remaining cylinders of the engine operate in a non-port heatingmode.
 18. The system of claim 17, wherein the controller is furtherconfigured to resume the port heating mode by successively operatingsubsets of at least two cylinders in the port heating mode until allcylinders within the first bank have been operated in the port heatingmode at least once.
 19. The system of claim 16, wherein the age of theengine is a calculated or measured megawatt-hours of the engine.
 20. Thesystem of claim 16, wherein the engine is operating in a locomotive.